1. Field of the Invention
The present invention relates to a liquid crystal display (LCD) device, in particular, to a liquid crystal display device with an electrostatic discharge protection circuit.
2. Description of the Prior Art
In recent years, the thin-film transistor (TFT) panel technology continues to progress. For example, the driving circuit integrated into the panel, such as system on glass (SOG) technology, can be manufactured by amorphous silicon (a-Si) process, low-temperature poly-silicon (LTPS) process, or InGaZnO (IGZO).
Recently, the high-resolution liquid crystal display devices with slim border are developed increasingly. No matter the TFTs are manufactured by amorphous silicon (a-Si) process, low-temperature poly-silicon (LTPS) process or InGaZnO (IGZO) metal-oxide process, etc., the gate driving circuit is a key factor of the border width. For example, the gate driving circuits integrated into the panel to replace the gate driver IC can reduce the area of routing lines in the non-display region, so that the width of the border can be reduced. In addition, the cost can be reduced because the gate driver IC and the IC bonding process are not needed in the technology of gate driving circuits integrated into the panel. However, with the design of gate driving circuits integrated into the panel, the electrostatic discharge damage to the driving circuit and the pixel circuit may become serious.
Conventional liquid crystal display mainly adopts the thin-film transistor diodes, metal-insulator-metal diodes, lightning rod pattern designs or series impedance type, etc., to prevent the pixel circuits in the LCD panel from being damaged by the electrostatic discharge (ESD). However, the ESD event may occur anywhere in the panel and damage the devices in the panel. For example, if the ESD event occurs in the conductive line between the controller and the gate driving circuit, the ESD may damage TFT elements of the gate driving circuit and the gate driving circuit may not function properly if the characteristics of the TFT element are abnormal due to the ESD damage.